Safety-valve.



H. B. ASHLLMA L1. S. 50HNS0N.

SAFETY VALVE. APPLICATION FILED 1AN.23.1A9I4. RENEWED IAN. 13.19I

1,f216,919. y Patented Feb. 20,1917.

j A TTORNEYS UNITED sTATns- .PATENT OFFICE. u

HEnvnY sowas ASHELMAN AND .mim sannronn manson. or renee, NORTH DAKOTA.

sarnTYfyALvn...

.Specification of Letters Patent.l

Patentes. Fen. 2o, 1917.

Application meakranuary 2s, 1914, seriai No, 813,890. Renewed January 1e, 191%'. .serial Nafmaaaa.

North Dakota, have invented nevs7 and use-v ful Improvements in Safety-Valves, of

- which the following is a specification.

Our ,invention relates to safety valves for e general use, and more particularly to safety valves of a type suitable forservice in connection with vehicle tires.. A

Among the 'various objects sought to be accomplished by our improvements are the following:

I, To enable the valve to automatically give relief in the event `that the pneumatic pressure Within the tire exceeds a; predeter minedy n'ormal'limit, so as to avoid excessive or dangerous pressure of air Within the tire, nomatter Whether suchp'ressure be due to the act of inflating the tire, or accumulated by other means, for instance by `eX- pansion of air within the tire due tothe apkplication of heat.

II. To provide'various vpart-s and so combine lthe same as toinerease thegeneral ef'iciency of safety valves.

Reference is made to the accompanying drawing, forming a part of this specifica'- ytion, and in which llike ynumerals indicate like parts. .r

Figure 1 is a substantially central vertical section through our safety valve.

lthe upper portieriL thereof. y Fig. 3 is a crosssectio'n on the line 3-3 `oliig.' 2, looking vin the direction of the Fig. 2 is a :fragmentary side elevation of 'A barrelfl, having the proximate general yform ofa cylinder, isprovided withl an er1-- i larged portion 5, and with a passage 6. This 6, this compartment being bounded partially `by an annular shoulder 11. `The upper inner surface of the barrel 4 is provided with a. thread 12.

used for turning it.

hich the barrel 4 isv Encircling the barrel located `in an -rlai-ly in Fig.

`A retoluble bushing of substantially cylindrical forni, is threaded externally to mate the thread 1&2, and is fitted Within the upper end of the barrel e. The bushing 18 is provided with grooves 18a, in this i11- stance four in number, which are located parallel Witheach other and with the geometrical `axis of the bushing. These grooves cross the threads carried by the bushing 1S, as will be understood from Fig., 2. The bushing 18 .is provided with Va ymilled head lto 19 ol. annular' form, integral With it, and

This milled head's provided with openings 20, extendingl radi# ally into it, and having a form suitable for the purpose of' facilitating the application of a. pin or Wrench to the head 1-9 in order' to l turn the same, and also serving as gage.

Another.gagegniarlr et is placed upon ythe upper yportion of the barrel 4l. yWhen the. `gage .mark :20/is inr registry With thega e mark 4a, the locking pin 16 fits into the at n 'd l Fig. 8. There are as manv openlngs 20, or

jacent grooveglS, as will be understood fromA gage markscarried by thevhead 19, as there are grooves 18a; By turning the head .19, and with it the bushing/185the bushing is brought into` such position that thelocking pin 1 6 ts into some one of the vertical grooves 18, and. when vthis takes place the gage mark 4? in registry With one of the openings or'gage marks 20. f

Located within the barrel `4t and concentric thereto is a sleeve 21', provided with an n annular beadQQQserving as ar shoulder. An' annular packing 23 of rubber is carried by .the sleeve .21 and secured to the shoulder just mentioned. This packing rests upon the annular shoulder llwhen the movable This sleeve is provided with a neck por tion 25, the latter adjacent its upper end being provided externally with a thread 26.

. 36, which is in alinement' with .i cap 28 is threaded internally, 'and revolubly fitted upon the upper end of the neck portion 25, and carries a rubber packing27 having the form of a disk, and adapted, 1111- der pressure oi thecap 28, t-o close the upper end of the neck'25 so Vas td render 'ihr same air tight. The neck portion25 is provided internally with a thread-29, and isfurther.

provided with a substantially'frustoconical portion 30, and with a cylindrical passa 31 of the same diameter as the lower endo the portion 30. The passage 31 communicates n ith a passage 32 of a still smaller diameter, and extending to the bottom of the sleeve` 21. The sleeve 21, adjacent the upper end of the passage 32, is provided with ya number of lugs 34, and encircling these lugs is an annular space 33, forming practically a continuation of the passage 31.

Revolubly mounted within the neck portion 25, and threaded externally,"is` a sleeve 3), provided externally with a thread mating the thread 29. The sleeve 35 is further provided with an axially disposed passage the passage 21 valve stem 37 extends through the passage 31, and into the passage 32, as well as into or through the passage 36. The sleeve is provided with a substantially frusto-conical portion 35a, and with' a substantially truste-conical gasket 38, adapted to lit against the portion 30 of the neck 25.

A valve 39, having the form of a disk, is mounted upon the valve stem 37. A spiral sprin l0 engages the valve 39, and encircles a portion of the valve stem 37. An annular guide plate 41 encircles the valve stem 37, and is engaged by the spring 40. The valve stein 3T' carries a. head 42, serving the pur pose of a limiting stop, in order to prevent the plate 4-1 from becoming detached from the valve stem 37.

The sleeve 21 is provided with an annular shoulder 43, which is adapted to lodge against the lower end of the bushin 18 whenever the sleeve 21 is lifted or raiser? 11pwardly, according to Fig. 1.

A spiral spring 44 encircles .the lower portirr of the sleeve 21, and constantly engages the: annular bead 22 thereof. 'The spiral spring in question also constantly engages the lower end of the bushing 18, so that the tension of the sprin in question may be controlled, at the wil of the operator, by rotation of thev milled head 19.

The sleeve 35, the valve 39, the-valve stem 37, the spiral spring 40 and the cap v28, all carried by the sleeve 21, are for purposes of adjustment, entirely independent of the spring i4, and movements of 'the sleeve 21"` tak'e place independently of the parts just enulinerated as inclosed within and carried by this sieeve.

The lower end of the sleeve 21 is essentially a valve, and the shoulder 1l is a valve seat against which this. valve is adapted to of the spring 44.

The operation of our device is as follows:

The parts being assembled as shown and described, and thespiral springs 'being adjusted as to tension', the safety valve 1s mounted in position ready for use, for instance upon avehicle tire. For this purpose the threaded passage 7 is brought urto engagement with a threaded sleeve carried by lthe vehicle wheel and communicating wit the tire. y

In order to inflate the tire, the cap 28 is removed, and the upper end of the sleeve 2.1 is connected with an air pump. Air 1s forced downwardly through the passages 36, 31 and 32, through the screen 8 and into the tire. The air while passin through the passage 36, disenga s the va ve 39 from its seat-that is, from t e'lower end of the frusto-conical portion 37 of the lsleeve 35, and in so doing slightl compresses the spiral spring 40. The c osure of the valve 39 prevents the retrogression of the air. 1 The tire being'inated Ito a predetermined tension, n o more air can be forced into the tire. This is because the air pressure in the lower end the passage 10 and out through the grooves 18 into the atmosphere. .l

The operator by turningthe milled head 19 and with it the threaded bushing is, sa above described, can confer upon the .spring 44, such tension as will permit the @inprocsure within the tire to reach apredetennined desiredmaximum, and no more. l The operator by turning the sleeve-3 5 cm within limits permitted by the elasticity of the gasket 38, adjust theposition of this sleeve relatively to the slpeve 21, and by so doin can "control the, tensionof the spring 40. y adjusting the Itension of this spring, the operator can adjust the sensitiveness of the valve 39, relatively to the air Jressure 1 15 -barrel having one end internally threaded,

valve mechanism carried thereby, ya. spring holding said valve against said for normally maintaining said valvewmeehanism in a predetermined position, a bushing exteriorly threaded and lscrewing linto the barrel, said bushing engaging saiduspring Y lfor the purpose of conferring different degrees of tension upon said spring', said bush-v .ing being provided with groovesextending o across the threads thereof, a spring ring earried' by said' barrel, and a locking pin earned by said spring ring for fitting into some one of said grooves, inorder to locksaid bushi' ingirelatively'to said barrel.

2. ln a safety valve,4 the combination ofa barrel having one end' internally threaded and provided with a valve seat, a 4sleeve eX- v. tending into said barrel and provided With a valve for'engaging said valve seat, means for admitting air through said sleeve and for preventingI retrogression` l,ofsaid air through said sleeve, a spring for normally seat, k.a bushjf" ing exteriorly threaded and screwing `into the barrel, said bushing engaging said spring vfor placing said springunder different degrees of tension in order tocontrol the v sensitiveness of said valve relatively to said ing provided with grooves extending` across the'threadsI thereof, a spring ring carried byy said barrel and Y valve seat,` said bushing provided? with a. lolzking pin extending through the wall of `said barrel and formed to t into any o f 'said grooves, and indicatf ing mechanism for diselosing when any one i.

of said ing pin. s

3. In' a safety valve, a barrel having its upper end internally threaded and yprovided with a valve seat adjacent its lower end, a

bushing exteriorly threaded and screwinggrooves is in registry with said locknormally engaging the valve- 'seat of the barrel, said sleeve having an ex terior bead at its lower end and having its upper end reduced and extending through the bushing, a spring surrounding the sleeve between the head1 and the inner end of the bushing, a second sleeve ad'ustably secured inathe upper reduced end o the iirs't sleeve and having its inner end forming a valve -seatl and a spring pressed valve 1n the re-I ducedY end of the first sleeve andl seating on the valve seat at the inner end of thesecond sleeve,

Hnnvnv Bowes ASHELMAN.

Jenn sANDFonD JOHNSON.

" Witnesses:. i. '4

L. C. Moonn, 

